Computer Science Canada How do you make this line into a circle?

Author:  santabruzer [ Wed Dec 10, 2003 11:31 pm ]
Post subject:  How do you make this line into a circle?

Hey!
Just wondering.. how you would go about make a line draw a cicle.. as in like
 code: for i : 1 .. 360 drawline (300, 225, i, 100, 7)  delay (10) end for

would draw a triangle....

 Author: AsianSensation [ Wed Dec 10, 2003 11:32 pm ] Post subject: equation of a circle, as in x^2 + y^2 = r^2 sub in values for x and find y, then draw it from a center point.

 Author: Schaef [ Wed Dec 10, 2003 11:34 pm ] Post subject: To draw a circle you use "Drawoval" or "Drawfilloval" then in brackets you put (x coor. of circles center, y coor. of circles center, radius, radius, colour)

 Author: santabruzer [ Wed Dec 10, 2003 11:37 pm ] Post subject: the problem is that i knew that, but have no idea how to do it.... i'll try and figure it out.. hopefully..

Author:  Tony [ Wed Dec 10, 2003 11:48 pm ]
Post subject:

well you graph circle using y^2 = r^2 - x^2
 code: for i:-50..50 Draw.Dot(i+100,round(sqrt(2500-i*i))+100,red) delay(10) end for for decreasing i:50..-50 Draw.Dot(i+100,-round(sqrt(2500-i*i))+100,red) delay(10) end for

and just use those outer coordinates as your second point for the line

 code: for i:-50..50 Draw.Line(100,100,i+100,round(sqrt(2500-i*i))+100,red) delay(10) end for for decreasing i:50..-50 Draw.Line(100,100,i+100,-round(sqrt(2500-i*i))+100,red) delay(10) end for

Though it's not a perfect fill

You're better off using Draw.FillArc
 code: for i:1..360 Draw.FillArc(100,100,100,100,i-1,i,black) delay(10) end for

 Author: santabruzer [ Wed Dec 10, 2003 11:56 pm ] Post subject: Thanx.. .. wonder why it ain't a perfect fill... (maybe should've paid attention at math class)

Author:  Homer_simpson [ Thu Dec 11, 2003 12:11 am ]
Post subject:

how bout this one?
 code: View.Set ("offscreenonly") var y := 0.0 for decreasing r : 6000 .. 50 by 20     cls     for x : -80 .. 80         if (r ** 2) >= (x ** 2) then             y := sqrt ((r ** 2) - (x ** 2))             drawdot (x + 320, round (y) + 200 - r, 12)             drawdot (x + 320, round (-y) + 200 - r, 12)         end if     end for     View.Update     delay (10) end for

 Author: santabruzer [ Thu Dec 11, 2003 8:49 am ] Post subject: nice effect... but i wanted something a lot simpler.. like a line redrawing over and over to form a fill oval... i guess you can't do that..

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